CRYSTAL CHEMICAL RESEARCH POTENTIALS OF DATABASE ON PROPERTIES OF MATERIALS FOR ELECTRONICS. S.A. Magarill, S.V. Borisov, N.V. Podberezskaya, L.M. Volkova, Institute of Inorganic Chemistry Sib. Branch RAS, Novosibirsk, Russia, Institute of Chemistry FE Branch RAS, Vladivostok, Russia
Using the data of the 'Crystal Structure' section of DB PME [Zh. Strukt. Khim. (Rus.), 1995, v.36, N3, p.559-562] as the base, we have carried out a crystal chemical analysis of some high-temperature superconducting compounds, considered accumulation and transfer of charges in superconducting cuprates, predicted new copper-free high-temperature superconductors, and published reference books involving reviews, data and bibliography. Crystal chemical calculations were performed and correlations were found for crystal structures of copper-containing phases, copper-free oxides superconductors, oxide bronzes, and rare-earth chalcogenides.
A structural similarity between various compounds was revealed by using planar atomic nets. These allowed us to compare structures, separate the planes with a densest atomic filling, and estimate a possible heteroepitaxy, i.e. to predict a possibility of the epitaxial growth of a target material on the substrate oriented in a certain way.
The structures of inorganic coordination compounds were considered as the packing of the quasi-spheres of the Ref radius which form cubic (CaF2 and NaCl or combinations thereof) or hexagonal structure types. The Ref radius of the basic sphere was applied to estimate the lattice parameters of the hexagonal (ah=2Ref) and cubic (ac=22 Ref) unit cells. The estimated lattice parameters are comparable with the observed ones. This suggests a possibility for co-crystallization and the isomorphous substitution. We observed a successive conversion from the cubic to triclinic symmetry with preserving packing rules of the complex centers as the most 'hard' scattering fragments.
These results can be used as the elements of the chemical design required for an aimed synthesis of crystals with specified properties.
*Magarill S.A., Borisov S.V., Podberezskaya N.V. et al //(Zh. Struct. Khim., 1995, v.36, N3, p.559-562).